overwhelms porous paving.. and so storm ponds are still needed (but smaller)... unless there are also engineered swales...essentially medians and other areas that are depressed - (i.e. lower than the pavement surfaces) that receive and sequester and filter into the soil rather than feed it to storm water facilities...check it out:http://www.forester.net/sw_0305_porous.htmljust GOGGLE porous pavem